Conventional in vitro fertilization (IVF) techniques of sperm sorting consist of either (1) a direct swim-up method or (2) density gradient separation. For the direct swim-up method, sperm DNA integrity may be compromised and low yield of recovered motile spermatozoa was observed in some studies [A. Zini, et al., “Influence of semen processing technique on human sperm DNA integrity”, Urology, 56 (2000) 1081-1084]. For the density gradient separation technique, repetitive centrifugation and re-suspension of the seminal pellet may cause damage to motile spermatozoa by reactive oxygen species [R. J. Aitken, J. S. Clarkson, “Significance of reactive oxygen species and antioxidants in defining the efficacy of sperm preparation techniques”, J. of Androl., 9 (1988) 367-376].
Microfluidic technology has shown great promise as a revolutionary platform for in vitro fertilization (IVF). Depending on the design of microfluidic devices, there are many possibilities for which the microfluidic devices could simplify or improve the current IVF procedures.